From b3dd0aba3d2bf0b22280303ef6f068e976e31888 Mon Sep 17 00:00:00 2001

From: Father Chrysostomos <sprout@cpan.org>

Date: Sat, 2 Jul 2016 00:08:48 -0700

Subject: [PATCH] [perl #128508] Fix line numbers with perl -x

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When lex_start is invoked with an SV and a handle pointer, it expects

the SV to contain the beginning of the code to be parsed.  The handle

will be read from for subsequent code.

The -x command line option happens to invoke lex_start with two non-

null pointers like this (a line and a handle), since, to find the

#!perl line, it has to read that first line out of the file handle.

There is a line of code in lex_start that adds "\n;" to the buffer

goes back to 8990e30710 (perl 5.0 alpha 6) and string eval fails

catastrophically without it.

As of v5.19.1-485-g2179133 multiple lines are supported in the current

parsing buffer (PL_linestr) when there is a file handle, and as of

v5.19.3-63-gbf1b738 the line number is correctly incremented when the

parser goes past a newline.

So, for -x, "#!perl\n" turns into "#!perl\n\n" (the final ; is skipped

as of v5.19.3-63-gbf1b738 if there is a handle).  That throws line

numbers off by one.

In the case where we have a string to parse and a file handle, the

extra "\n;" added to the end of the buffer turns out to be completely

unnecessary.  So this commit makes it conditional on rsfp.

The existing tests for -x are quite exotic.  I have made no effort to

make them less so.

Signed-off-by: Petr Písař <ppisar@redhat.com>

---

 t/run/switchx.aux | 7 ++++---

 t/run/switchx.t   | 4 ++--

 toke.c            | 3 ++-

 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/t/run/switchx.aux b/t/run/switchx.aux

index b59df4a..106b2f7 100644

--- a/t/run/switchx.aux

+++ b/t/run/switchx.aux

@@ -17,11 +17,12 @@ still not perl

 #!/some/path/that/leads/to/perl -l

-print "1..7";

+print "1..8";

+print "ok 1 - Correct line number" if __LINE__ == 4;

 if (-f 'run/switchx.aux') {

-    print "ok 1 - Test file exists";

+    print "ok 2 - Test file exists";

 }

-print "ok 2 - Test file utilized";

+print "ok 3 - Test file utilized";

 # other tests are in switchx2.aux

 __END__

diff --git a/t/run/switchx.t b/t/run/switchx.t

index bcea3d0..4e57d04 100644

--- a/t/run/switchx.t

+++ b/t/run/switchx.t

@@ -15,9 +15,9 @@ print runperl( switches => ['-x'],

 # Test '-xdir'

 print runperl( switches => ['-x./run'],

                progfile => 'run/switchx2.aux',

-               args     => [ 3 ] );

+               args     => [ 4 ] );

-curr_test(5);

+curr_test(6);

 # Test the error message for not found

 like(runperl(switches => ['-x'], progfile => 'run/switchx3.aux', stderr => 1),

diff --git a/toke.c b/toke.c

index aebeebb..7e77fae 100644

--- a/toke.c

+++ b/toke.c

@@ -723,7 +723,8 @@ Perl_lex_start(pTHX_ SV *line, PerlIO *rsfp, U32 flags)

 	parser->linestr = flags & LEX_START_COPIED

 			    ? SvREFCNT_inc_simple_NN(line)

 			    : newSVpvn_flags(s, len, SvUTF8(line));

-	sv_catpvn(parser->linestr, "\n;", rsfp ? 1 : 2);

+	if (!rsfp)

+	    sv_catpvs(parser->linestr, "\n;");

     } else {

 	parser->linestr = newSVpvn("\n;", rsfp ? 1 : 2);

     }

-- 

2.5.5